In 1971, a comprehensive study was made of mathematics and reading achievement in the Borough of North York, Ontario. In 1974, a replication and followup study was carried out. The purposes of the study were to replicate the 1972 study, and to obtain a measure of growth in reading and mathematics achievement between grade 3 and grade 5, over the two year time period. In both years, the Metropolitan Achievement Test, the Sequential Tests of Educational Progress, and the School and College Ability Test were used. The results indicated that North York achievement in both reading and mathematics compared favorably with the American norms in all grades tested, and the average growth over the two years grade 3 to grade 5 was above that expected in both reading and mathematics. (Author/BW)